Photolithographic patterning is a well-established technology in the manufacturing processes of various integrated circuits, including integrated circuits with semiconductor devices, and liquid crystal display panels. During photolithographic patterning, a photosensitive resist, such as a developable polymer material, is coated onto a surface of a base material, which may be a substrate or a material supported by the substrate, to deposit a photoresist material, also referred to in the industry and herein as a “resist material.” Before application of the resist material, the surface of the base material may first be coated with a primer, such as hexamethyldisilazane (HMDS), to promote adhesion between the resist material and an otherwise hydrophilic base material surface. When the resist material is applied, the resist material adheres to the primer on the base material through polar and Van der Waals forces. While application of the primer increases adhesion between the resist material and the base material, the primer does not increase surface area interactions between the resist material and the base material.
The resist material is then selectively masked and exposed to an energy source (e.g., radiation, such as ultraviolet light or an electron beam), so that select segments of the resist material are exposed while other masked segments of the resist material are not exposed. Subsequently, the resist material is subjected to a developer, which dissolves, so as to enable removal of, either the exposed or non-exposed segments of the resist material, depending upon the type of resist employed, e.g., a positive or a negative resist, and the type of develop process employed, e.g., positive tone develop or negative tone develop. If the resist material is a positive resist and a positive tone develop process is used, the exposed portions are dissolvable and therefore removable by the developer. If the resist material is a positive resist and a negative tone develop process is used, the non-exposed portions are dissolvable and therefore removable by the developer. If the resist material is a negative resist, the non-exposed portions are selectively dissolvable and therefore removable by the developer. The resist material remaining after development protects still-covered regions of the base material from effects of subsequent etch or implant operations.
Such photolithographic processes may be used to pattern materials with particularly small dimensions, e.g., with lines thinner than 250 nanometers in width. In such small-dimensioned lithographic processes, capillary forces attributable to the composition and reaction of a resist material during development of the resist may be greater than adhesive interactions between the resist and the underlying material with which the resist is in contact. Line collapse, toppling, or both may occur, causing distortion of the shape of the remaining segments of the resist material, i.e., the non-developed resist material. With decreasing critical dimensions in line-space patterns, line collapse is becoming a recurring problem, for example in the case of 193 nm photolithography.